Electrical insulating medium



W. W. HALE ELECTRICAL INSULATING MEDIUM Filed June 5, 1926 Patented Dec. 30, 1924.

UNITED STATES WILLIS W. HALE, 0F CLEVELAND, OHIO.

ELECTRICAL INSULATING- MEDIUM.

Application filed June 3,

To all whom it may concern:

Be it known that I, WILLIs W. HALE, citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electrical Insulating Mediums, of which the following is a specification.

The present invention relates to electrical insulating mediums, and has for its object to provide a novel electrical insulating substance which is a good conductor of heat and which can accordingly be used to great advantage in the manufacture and construction of electrical heating and cooking appliances.

Further objects of the invention are to provide a heat conducting electrical insulating substance which can be produced at a comparatively small cost, which can be handled and worked in the same manner as any insulating medium, which will not break down under the action of the electric current, and which is an effective and dependable electric insulator.

The invention is explained more fully in the following description, and in connection therewith reference is to be had to the accompanying drawings, in which Fig. 1 is a perspective view-of several superposed thicknesses including outside sheet metal plates and inner insulating thicknesses which embody the invention and are utilized to insulate an electric resistance wire from the sheet metal plates, portions being broken away and shown-in section.

Fig. 2 is a perspective View showing this same assemblage of elements as reversely bent back and forth toprovide a portion of an electric heater, portions being broken away and shown in section.

Corresponding and like .parts are referred to in the following description and indicated in all of the views of the drawing by like reference characters.

In carrying out the invention some suitable electrical insulating medium having a porous or fibrous bod or otherwise adapted to be treated with a llquid is saturated with a solution of silicate of soda or water glass (NasiO and then permitted to become thoroughly dry. Ithaslbeen found in practice that an. electrical insulating medium which has been thus treated with silicate of 1920. Serial No. 386,193.

soda retains practically all of its electrical insulating properties although it is thereby rendered a good conductor of heat. The original insulating medium thus treated may be asbestos, fire clay, or any other analogous msulating material, and the finished product is very useful in the construction of electric heaters and cookers where it is necessary to insulate the electric current and at the same time conduct the heat away from the resistance element as expeditiously and with aslittle retention as possible.

In the drawings, the reference character A designates a sheet of electrical insulatmg material, such as asbestos, which has a porous or fibrous formation and can accordingly be readily saturated with a liquid medium. Preparatory to use this sheet A is treated with a solution of silicate of soda. A resistance wire 1, which may have any suitable composition, may be interposed be tween two of these insulating sheets A, and the insulating sheets in turn interposed between sheet metal plates 2. In Fig. 2 the sheet metal plates are shown as reversely curved back and forth, although it will be understood that this is merely illustrative of one out of many practical uses for the invention, The insulating sheets A form effective electrical insulators for the resistance wire 1, although the heat is readily conducted to the sheet metal plates 2 which have alarge superficial area and quickly radiate the heat in the desired manner.

WVhat I claim as new and desire to secure by Letters Patent is:

1. An electric heater including a resistance element, a radiating housing therefor, and an insulating filler interposed between the opposite faces of the resistance element and the housing and in an intimate engage ment with both of said elements, said insulating filler being treated with silicate of soda to render it a conductor of heat.

2. An electric heater including a resistance element, opposite metallic radiating plates, and asbestos insulating material insaid plates and in an intimate engagement with the said elements, said asbestos insulating material having been treated with silicate of soda to render it a conductor of heat.

In testimony whereof I affix my signature.

WILLIS W. HALE.

' terposed between the resistance and each of 

